coldfusion21 Posted October 14, 2009 Share Posted October 14, 2009 Car is a 1990 Subaru legacy. ej22 2.2 liter motor. Thermostat went tits up. Pulled it to make sure that was the problem, sure enough without a thermostat it would heat up real slowly and maybe get close to operating temp in the summer. Well i decided just to leave it that way for a couple months. Fast forward to September where the car never heats up and i have no heat most of the time. I replace the thermostat with an OE one. Do a decent bleed and all seems well for one full week. Then i start to get random overheats. Car will be at operating temp for 5 minutes or maybe 20 minutes then the heat cuts out and the temp gauge starts to rise. If i let it idle it cools back down. Radiator cap is brand new. Just did a compression test today, 160-175 on all four. Bled the system pretty well the other day, per all the subaru forum instructions and it ran for about 15 miles before overheating. Did a half rump roast job today and it has been fine all day. Last thing i need to check into is flushing my radiator to see if its clogged. No oil in water or water in oil either. Anyone else have any ideas? I'm about ready to pull my thermostat again, but i really do like my heater... Quote Link to comment Share on other sites More sharing options...
edrach Posted October 15, 2009 Share Posted October 15, 2009 What's the mileage on the car? For a 1990, water pump or radiator failure would not be out of line. It could still be a bubble in the coolant. But you need to do more testing. Quote Link to comment Share on other sites More sharing options...
Danbob99 Posted October 15, 2009 Share Posted October 15, 2009 If the coolant level is always full and you are still getting an overheat condition, it pretty well narrows it down to cooling system components. (rules out headgaskets and other leaks) I would check the radiator, see if it's devolping any hot spots accross the surface of it. Feel to see that it blows warm air when the cooling fans are kicked on. Check to see that the cooling fans are indeed kicking on. Let them come on at idle and monitor how long they stay on for. Should be around 30 seconds. (make sure your defrost and ac are off) Lastly, you could have water pump issues. I've seen impellers seperate from the shaft of the water pump, but this is a real rare issue. Report back with your findings! Good Luck, Dan Quote Link to comment Share on other sites More sharing options...
coldfusion21 Posted October 15, 2009 Author Share Posted October 15, 2009 Ok, well i get good water pump flow, and the random-ness of this problem has lead me to believe water pump is not the issue. car is high mileage, 244k. the proper coolant mix has also not always been followed... fans kick on strong, run for just a bit and kick off when the car is functioning normal. I frequently hear them running when it over heats too. I think that system is ok. Air over the radiator has always felt a bit cold. I'm not sure that it isn't consuming any coolant. I get some light steam out the back and due to it overheating it fills the expansion tank and doesnt always suck it all back in. so it can be hard to keep an eye on. but if it is consuming coolant its not much. the car runs great, doesnt leak at all on the ground. Quote Link to comment Share on other sites More sharing options...
Suzam Posted October 15, 2009 Share Posted October 15, 2009 If it pushes out more coolant into the overflow than it takes back after cooling, then air is replacing the coolant in the system. If the heat cuts out before you over heat then there is no coolant in the heater core, again air. Have you change out all the heater and radiator hoses? A partially collapsed hose could also be a problem. If the hoses are good you might have a blown headgasket. You could get a hydrocarbon test to confirm. Quote Link to comment Share on other sites More sharing options...
coldfusion21 Posted October 15, 2009 Author Share Posted October 15, 2009 Haven't messed with the hoses, but they all seem to be in decent condition, not spongy or anything. Whats this hydrocarbon test you speak of? Quote Link to comment Share on other sites More sharing options...
Suzam Posted October 15, 2009 Share Posted October 15, 2009 A hydrocarbon test checks the coolant for hydrocarbons created by combustion. If present then gases from the cylinders are entering the coolant through a bad seal in the combustion chamber. The hot gases that get pushed passed the headgasket force the coolant out of the system. Quote Link to comment Share on other sites More sharing options...
michaelbteam Posted October 15, 2009 Share Posted October 15, 2009 (edited) I had the elusive HG issue with a 99 Outback. [2.5] Had to drive it 20 miles into the mountains every morning, from 4500 feet to 8000 feet and did not have time to repair it in the winter. It would not quite overheat but would push coolant into the overflow. I ran it with no thermostat and simply dumped the full oveflow back into the tank every night after work and drove it home with no issues. This problem was so hard to diagnose initially--it would not produce symptoms during a 15 minute high RPM test in the radiator shop. Finally sold the car to someone who felt like fixing it, no more 2.5 for me. Edited October 15, 2009 by michaelbteam typo Quote Link to comment Share on other sites More sharing options...
coldfusion21 Posted October 15, 2009 Author Share Posted October 15, 2009 A hydrocarbon test checks the coolant for hydrocarbons created by combustion. If present then gases from the cylinders are entering the coolant through a bad seal in the combustion chamber. The hot gases that get pushed passed the headgasket force the coolant out of the system. sorry i guess i more so meant is this a test you can buy or is it something special a shop can only do? That sounds like the ticket if i can get my hands on one. Well i know the 2.5 has headgasket issues but this isnt a 2.5 and its much older so i think that opens it up to other issues like a clogged radiator or something along those lines. Quote Link to comment Share on other sites More sharing options...
Setright Posted October 15, 2009 Share Posted October 15, 2009 Cabin heat goes. Engine overheats. High rise in the expansion tank. Headgasket. Quite conclusive evidence. Been there, paid the money, happy motoring from then on. Quote Link to comment Share on other sites More sharing options...
Suzam Posted October 15, 2009 Share Posted October 15, 2009 A higher mileage older 2.2 can develop a bad headgasket. Any motor can have a bad one, no car is immune. A good mechanic can do a hydrocarbon test for you, I'm not sure if it's a "do it yourself" test. If it comes up positive, with the age and mileage on your car, you may be looking for a replacement motor if the body and all else is in good enough shape to keep on the road. Quote Link to comment Share on other sites More sharing options...
Sturgn Posted October 15, 2009 Share Posted October 15, 2009 Hi I'm new to this forum and was wondering where it was that you found the proper way to bleed the cooling system? I am having problems with my new used 98 OBW. 101.000 mi. :-\ Quote Link to comment Share on other sites More sharing options...
Olnick Posted October 15, 2009 Share Posted October 15, 2009 . . . was wondering where it was that you found the proper way to bleed the cooling system? Welcome aboard Sturgn. Your best friend here on USMB is the search function up top. Tons of Subaru information. Choose "advanced search," type in "burp" or "burp coolant," select "New Gen Forum" and hit "search." Good luck. Quote Link to comment Share on other sites More sharing options...
coldfusion21 Posted October 15, 2009 Author Share Posted October 15, 2009 A higher mileage older 2.2 can develop a bad headgasket. Any motor can have a bad one, no car is immune. A good mechanic can do a hydrocarbon test for you, I'm not sure if it's a "do it yourself" test. If it comes up positive, with the age and mileage on your car, you may be looking for a replacement motor if the body and all else is in good enough shape to keep on the road. Well, the body is trashed and the interior leaves a bit to be desired. But its my only (sorta) running car now. I will probably end up doing the gaskets myself. Is this a pull the engine for sure kinda deal? Quote Link to comment Share on other sites More sharing options...
Setright Posted October 16, 2009 Share Posted October 16, 2009 Welcome aboard Sturgn. Your best friend here on USMB is the search function up top. Tons of Subaru information. Choose "advanced search," type in "burp" or "burp coolant," select "New Gen Forum" and hit "search." Good luck. Search for "Coolant replacement"...by me Post nr. 26...surefire http://www.ultimatesubaru.org/forum/showthread.php?t=21681&highlight=coolant&page=3 Quote Link to comment Share on other sites More sharing options...
ferret Posted October 16, 2009 Share Posted October 16, 2009 What kind of thermostat did you use? I hope it was a SUBARU brand. The OEM and aftermarkets have been known to cause overheating problems. Also they have to be installed in the correct direction. The Subaru thermostat is not expensive from the dealer, and you will see the spring/heat end is longer and sets deeper into the waterpump. This way it opens sooner and all the way when necessary. You may have any of the other problems discussed here, but I have come across an OEM thermostat causing problems in boxer engines more than once. Quote Link to comment Share on other sites More sharing options...
coldfusion21 Posted October 16, 2009 Author Share Posted October 16, 2009 What kind of thermostat did you use? I hope it was a SUBARU brand. The OEM and aftermarkets have been known to cause overheating problems. Also they have to be installed in the correct direction. The Subaru thermostat is not expensive from the dealer, and you will see the spring/heat end is longer and sets deeper into the waterpump. This way it opens sooner and all the way when necessary. You may have any of the other problems discussed here, but I have come across an OEM thermostat causing problems in boxer engines more than once. It wasn't purchased at the dealer but i was told it was OEM. Looked way better then the one it replaced. Was installed the only way it fit. Quote Link to comment Share on other sites More sharing options...
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